The idea of sharing a septic system with your neighbor
doesn't appeal to everyone. Yet, for builders, shared
systems make a lot of economic sense. While the
treatment system is larger than an individual system,
economies of scale create a substantial savings.
In Rhode Island, where we live, the high water table and
small lots typically necessitate the use of "alternative" septic
systems such as sand filters and biofilters, which treat
the effluent before it is pumped to the leach field (see
"Alternative Septic Systems," 1/97). The cost of equipping
ten homes with individual advanced treatment systems
runs between $100,000 and $120,000. But the ten-home
shared system described in this article will